NYC tunnel expansion the largest transportation project in U.S.

New York City is undergoing the biggest addition to its transportation system since Penn Station opened in 1910, Time reported. And as you can see above, the project has resulted in some amazing photos.

The project will create six miles of new tunnels connecting the Long Island Rail Road to Grand Central Terminal. It is the largest transportation project in the United States, with 32,000 feet of new tunnels expected to result from construction.

So far, workers have completed nearly 22,200 feet of tunnel, and plans are in place to excavate 10,000 linear feet of tunnels in Queens to connect the 63rd street Tunnel to the existing LIRR tracks in Sunnyside.

Though construction work began in 2006, the end date has been pushed back several times due to the complicated nature of the project. At this time, the tunnels are expected to open in 2019.